Saturday, July 29, 2017

Cork Taint in a Screwcap?

In my last post, I wrote about the difference between corks and screwcaps, about how the latter has significantly circumvented the problem of cork taint. Then the unexpected happened to me - I got a screwcapped wine that was corked!

One of these was corked
It was a gorgeous summer afternoon in Portland, and I was thrilled to find a new wine bar and bottle shop to try. We sat down at the patio, and I ordered a flight of three mid-range Oregon Pinot Noirs. I swirled the glass of the first wine, took a whiff, and immediately got that faint but unmistaken smell of wet cardboard. I took a sip, which confirmed that off-putting taste devoid of fruit and flavor. I tasted the other two glasses, and they were fine.

I took the corked wine back to the shop and waited patiently for the shopkeeper to finish his conversation with another customer. Then I told him discreetly that the wine was corked. He took it back and came out to the patio with a new bottle and a new glass. He twisted the screwcap off the bottle to pour me a new glass and said, "That wine was fine, but here's one from a newly opened bottle."

Now, I have up to now experienced only half a dozen corked bottles. While it was not a common occurrence to get a corked wine these days, the last three happened in the past year so I am unfortunately quite familiar with the smell and taste of a corked wine; the earlier two being a Brunello and a California Super Tuscan-style red. I have even tried the Saran wrap trick to remove the taint, which, I am sad to report, does not work.

I digress. Now how does a screwcapped wine get corked?

TCA
I mentioned in my last post that the main cause of cork taint is TCA (2,4,6-trichloroanisole), a compound that leads to a musty fungal or wet cardboard aroma.  TCA belongs to a family of volatile compounds called haloanisoles, that cause moldy aroma. There are other compounds (TBA, TeCA, and PCA) that may be responsible for the taint.

Haloanisoles may be transferred to the wine from contaminated materials in the winemaking facility, such as tank coatings, hoses, barrels, and oak chips. It can also be transferred to the polyethylene film, which is commonly used as a liner for screwcaps. So while opting for a screwcap over cork will significantly reduce the chance of cork taint, it does not eliminate it. In my limited sample size, it is one to five.

Here's another interesting factoid - the sensory thresholds of different tasters for haloanisoles may vary as well. So one taster can be highly sensitive to it while another may not find it quite as objectionable. A well-known sommelier once discovered that a rare and expensive bottle ordered at his restaurant was corked. Despite his offer and attempt to replace it with a different bottle, the diners claimed that not only was the wine fine, but it was delicious. At which point, he had to back off against his professional judgement.

My Verdict: Regardless of the closure used, if you believe that your wine is corked, trust your taste and take the wine back. Even if the wine merchant disagrees with you, he or she will likely still replace your wine. It is better than to be stuck with an off-putting wine.